FORMATION AND MODIFICATION OF MESOSCOPIC STRUCTURES ON GRAPHITE (HOPG) AND SILICON SURFACES BY MEANS OF SCANNING-TUNNELING-MICROSCOPY

This paper presents results of our experimental investigations of the adsorption and interaction of microclusters on some crystalline surfac es to form regular arrangements. Microclusters were produced and depos ited up to a monolayer coverage on the c-plane of graphite (HOPG) or S i(111) substrates by thermal evaporation, laser ablation, or depositio n from STM tip. A rectangular lattice arrangement of Se-n (n = 5-8) ri ng cluster has been fabricated for the first time on the HOPG. Also, a rrays of Au clusters with a well-controlled diameter, desired periodic ity, and size have been obtained by applying a sequence of voltage pul ses between the STM tip and the substrate. A variety of carbon cluster s have been produced by laser modification of C-60 fullerenes, and obs erved by means of scanning tunneling microscope (STM). Finally, variou s nanometer-scale structures have been modified by applying different bias voltages (between tip probe and sample) or induced by thermal tre atment.